Contact Probe for the Delivery of Laser Energy

ABSTRACT

Systems, devices, and methods for treating a glaucomatous eye are provided. An amount of pulsed laser energy is delivered to the pars plana of the eye by a hand-holdable device which comprises a hand-holdable elongate member and a contact member disposed on an end of the elongate member. A contact surface of the contact member is placed in direct contact with the eye so that a reference edge of the contact member aligns with the limbus and a treatment axis defined by the elongate member is angularly offset from the optical axis of the eye. The amount of pulsed laser energy delivered is insufficient to effect therapeutic photocoagulation but is sufficient to increase uveoscleral outflow so as to maintain a reduction from pre-laser treatment intraocular pressure. Amounts of pulsed laser energy will be transmitted to a circumferential series of tissue regions of the eye.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a Continuation of U.S. patent applicationSer. No. 16/369,477 filed Mar. 29, 2019; which is a Continuation of U.S.patent application Ser. No. 14/579,783 filed Dec. 22, 2014, now U.S.Pat. No. 10,292,868; which is a Continuation of U.S. patent applicationSer. No. 12/261,889 filed on Oct. 30, 2008, now U.S. Pat. No. 8,945,103;which claims priority to U.S. Provisional Appln. No. 60/983,811 filedOct. 30, 2007; the full disclosures of which are incorporated herein byreference in their entirety for all purposes.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention is directed generally to medical devices, systems,and methods, particularly for treatment of an eye. In particular,embodiments of the present invention are directed toward contact probesfor the delivery of laser energy, and more particularly to contactprobes that are used for lowering the intraocular pressure (IOP) inhuman eyes afflicted with glaucoma. Even more specifically, the presentinvention is directed toward laser therapy for lowering IOP inglaucomatous eyes via transconjunctival/transcleral ab-externo treatmentwith infrared laser energy directed to pigmented intraocular cells ofthe pars plana and/or the posterior portion of the pars plicata.

Glaucoma is a leading cause of blindness. Glaucoma involves the loss ofretinal ganglion cells in a characteristic pattern of optic neuropathy.Untreated glaucoma can lead to permanent damage of the optic nerve andresultant visual field loss, which can progress to blindness. The lossof visual field due to glaucoma often occurs gradually over a long timeand may only be recognized when the loss is already quite advanced. Oncelost, this damaged visual field can never be recovered.

Raised intraocular pressure (IOP) is a significant risk factor fordeveloping glaucoma. IOP is a function of production of liquid aqueoushumor by the ciliary body of the eye and its drainage through thetrabecular meshwork. Aqueous humor is a complex mixture of electrolytes,organics solutes, and other proteins that supply nutrients to thenon-vascularized tissues of the anterior chamber of the eye. It flowsfrom the ciliary bodies into the posterior chamber, bounded posteriorlyby the lens and the ciliary zonule and bounded anteriorly by the iris.Aqueous humor then flows through the pupil of the iris into the anteriorchamber, bounded posteriorly by the iris and anteriorly by the cornea.In the conventional aqueous humor outflow path, the trabecular meshworkdrains aqueous humor from the anterior chamber via Schlemm's canal intoscleral plexuses and the general blood circulation. In open angleglaucoma there is reduced flow through the trabecular meshwork. In angleclosure glaucoma, the iris is pushed forward against the trabecularmeshwork, blocking fluid from escaping.

Uveoscleral outflow is a non-conventional pathway that is assuming agrowing importance in the management of glaucoma. In uveoscleraloutflow, aqueous humor enters the ciliary muscles from the anteriorchamber and exits through the supraciliary space and across the anterioror posterior sclera. Uveoscleral outflow may contribute significantly tototal aqueous humor outflow.

Currently, glaucoma therapies aim to reduce IOP by either limiting theproduction of aqueous humor or by increasing the outflow of aqueoushumor. Medications such as beta-blockers, carbonic anhydrase inhibitors,etc., are used as the primary treatment to reduce the production ofaqueous humor. Medications may also be used as the primary therapy toincrease the outflow of the aqueous humor. Miotic and cholinergic drugsincrease the trabecular outflow, while prostaglandin drugs, for example,Latanoprost and Bimatoprost, increase the uveoscleral outflow. Thesedrugs, however, are often expensive, may have undesirable side effects,and may have compliance-dependent efficacy which diminishes over time.

Surgery may also be used to increase its outflow or to lower theproduction of aqueous humor. Laser trabeculoplasty is the application ofa laser beam to irradiate areas of the trabecular meshwork to increasefluid outflow. Cyclocryotherapy and laser cyclophotocoagulation aresurgical interventions to lower the production of aqueous humor. Thesesurgical interventions work by permanently destroying the ciliary bodyand related processes. Although they may be effective, these surgicalinterventions are normally used as a last resource in the management ofglaucoma due to the risk of the severe complication of phthisisbulbi—the often painful and unsightly atrophy and degeneration of aneye. Other adverse side effects may include ocular hypotony andinflammation of the anterior eye segment, which may be associated withan increased incidence of macula complications. Still other adverse sideeffects include transiet hyphaema and exudates in the anterior chamber,uveitis, visual loss, and necrotizing scleritis.

In laser transscleral cyclophotocoagulation, a continuous train of highintensity infrared laser energy is directed toward selected portions ofthe pars plicata region of the ciliary body, structures under theoverlying conjunctiva and scleral layers. Selected portions of theciliary body and related processes are permanently destroyed, therebydecreasing aqueous humor formation. Laser energy may be deliveredthrough the air by free beams directed through air to a patient seatedat a special slit lamp. Alternatively, laser energy may be deliveredthrough the use of fiber optic handpieces placed in contact with thepatient's eyeball. In both laser energy delivery methods, however,accurately aiming a laser toward a ciliary body of the eye can bechallenging for a surgeon. Thus, contact handpiece probes (for example,the G-Probe available through IRIDEX Corporation of Mountain View,Calif. and described in U.S. Pat. No. 5,372,595, the full disclosure ofwhich is incorporated herein by reference in its entirety) have beendesigned to facilitate the aiming of a laser toward the pars plicataregion of the ciliary body. The G-Probe, for example, has specialcontours that facilitate consistent placement of the probe relative tolandmark structures of the eye, thereby decreasing the likelihood ofincidental laser exposure to unintended structures. However, thepermanent destruction of portions of the ciliary body and the potentialfor phthisis bulbi and other adverse side effects remains unavoided. Thepotential pain associated with such treatments also generally justifieslocalized delivery of pain relieving agents to the posterior portion ofthe eye. Though alternative and potentially advantageous lasertreatments have been proposed, they have not been shown to providelong-term benefits, thereby limiting their use.

In light of the above, there is a need for laser-based methods anddevices for the treatment of glaucomatous eyes which avoid many of theshortcomings described above.

BRIEF SUMMARY OF THE INVENTION

Embodiments of the present invention provide systems, devices, andmethods for treating an eye, in particular examples, a glaucomatous eye.An amount of pulsed laser energy is delivered to the pars plana of theeye by a hand-holdable device. This device comprises a hand-holdableelongate member and a contact member disposed on an end of the elongatemember. A contact surface of the contact member is placed in directcontact with the eye so that a reference edge of the contact memberaligns with a reference feature of the eye, usually the limbus, and atreatment axis defined by the elongate member forms a predetermined,non-zero angle with the optical axis of the eye. Typically, amounts ofpulsed laser energy are transmitted to a circumferential series oftissue regions of the eye. The delivered pulsed laser energy isinsufficient to effect therapeutic photocoagulation but is sufficient toincrease uveoscleral outflow so as to maintain a reduction frompre-laser treatment intraocular pressure. Thus, permanent destruction oftissue structures in the eye and undesired thermal damage of adjacenttissue structures, both of which typically result from conventionallaser cyclophotocoagulation procedures, is avoided while significantdegrees of intraocular pressure reduction are, surprisingly, maintainedfor long periods.

Accordingly, an object of the present invention is to provide animproved laser energy delivery handpiece.

Another object of the present invention is to provide a laser energydelivery handpiece with a handpiece axis that is substantiallyperpendicular to the eye.

Another object of the present invention is to provide a laser energydelivery handpiece that has a contact surface with a single radius ofcurvature across the contact surface.

Still another object of the present invention is to provide a laserenergy delivery handpiece that has a contact surface with substantiallyno sharp edges.

A further object of the present invention is to provide a laser energydelivery handpiece with a contoured contact surface and a protrudinghemispherical laser output tip.

Still a further object of the present invention is to provide a laserenergy delivery handpiece

Another object of the present invention is to provide a laser energydelivery handpiece that allows the surgeon to precisely target theintended intraocular structures, such as the pars plana and parsplicata, and avoid misdirected applications by positioning it over thesclera in reference to a stable external anatomical landmark such as thelimbus.

A further object of the present invention is to provide a laser energydelivery handpiece that helps a surgeon to keep the direction of thelaser beam precisely pointed toward the internal intraocular, invisibletarget.

Yet another object of the present invention is to provide a laser energydelivery handpiece that allows delivery of treatment either with aseries of individual precisely-spaced applications and/or withcontinuously sliding 180° or 360° arc motions

Still another object of the present invention is to provide a laserenergy delivery handpiece that allows the surgeon to keep a consistentscleral indentation in order to maximize the transmission of the laserenergy through the conjunctiva-sclera layers, and to minimize thevariations of the divergence of the laser beam reaching the targetedciliary body structures, from the posterior pars plicata through thepars plana.

These and other objects of the invention are achieved in a laser energydelivery handpiece characterized by an axis and adapted to receive afiber optic for laser surgery on a patient's eye. The eye has a shapedsclera, a limbus and an optic axis. Portions define a contact surfacethat conforms to the shape of the sclera at the limbus when the axis ofthe handpiece forms a predetermined angle relative to the externalsurface of the eye. The contact surface conforms to the shape of thesclera at the limbus when the axis of the handpiece is substantiallyperpendicular to the eye.

In another embodiment of the present invention, a laser energy deliveryhandpiece receives a fiber optic for laser surgery on an eye and has aninput end, an output end, a top, a bottom and sides. The fiber optic hasan optic axis. The eye has a shaped sclera, limbus, and an optic axis.The handpiece includes a body for holding the fiber optic and acontoured end portion. The contoured end portion has an end surface withan opening for the fiber optic. The end surface conforms to the shape ofthe sclera at the limbus when the optic axis of the fiber optic issubstantially perpendicular to the eye.

An aspect of the invention provides a laser treatment method for an eye,the eye having a pars plana posterior to a pars plicata and a pre-lasertreatment intraocular pressure. An amount of pulsed laser energy isdelivered to the pars plana of the eye. The amount is insufficient toeffect therapeutic photocoagulation and is sufficient to increaseuveoscleral outflow so as to maintain a reduction from the pre-lasertreatment intraocular pressure. Typically, the amount is sufficient tomaintain the reduction from the pre-laser treatment intraocular pressuremore than 5 months after the pulsed laser energy is delivered. Theamount of energy will typically be delivered without direct posterioreye pain alleviating agent delivery, and without excessive pain.

Generally, a laser delivery tip of a probe is positioned in contact withan outer surface of the eye and the amount of pulsed laser energy isdelivered from the positioned probe so that the pulsed laser energy isoriented toward a first pars plana region and such that permanentthermal damage to the pars plicata is avoided. The eye has an opticalaxis, and the probe will typically be oriented so that the pulsed laserenergy is angularly offset from the optical axis when the tip of theprobe is positioned in contact with the surface of the eye. The probemay define a treatment axis along which the pulsed laser energy isdelivered, and the probe will typically be positioned so that thetreatment axis is generally perpendicular with the surface of the eyewhen the tip of the probe is positioned in contact with the surface ofthe eye.

To position the tip of the probe in contact with the surface of the eye,a reference structure of a contact surface of the probe may bepositioned in alignment with a reference feature of the eye. The laserdelivery tip will be disposed along the contact surface so that thepulsed laser energy is posterior to a limbus of the eye by over 2 mm.The first pars plana region to where the pulsed laser energy isdelivered may be posterior to the limbus by over 3 mm. The referencefeature of the eye will typically comprise the limbus, and the referencestructure of the contact surface will typically comprise an edgeseparated from the laser delivery tip by over 2 mm. The edge extendsbetween opposed lateral placement sides of the contact surface. Thepulsed laser energy is delivered to the first pars plana region whilethe probe is held at a fixed position against the eye. The probe may beincrementally moved laterally, with reference to the sides of thecontact surface, along the limbus so as to sequentially treat aplurality of circumferentially offset regions of the pars plana. Theoffset regions define angular widths about the ocular axis of from 5 to20 degrees. The pulsed laser energy may be delivered to the first parsplana region for at least about 1 second.

The pulsed laser energy will generally comprise pulsed infrared laserenergy, for example, laser energy having a wavelength of 810 nm. Thetotal laser energy directed to the pars plana will generally be lessthan 75 J. In some embodiments, the pulsed laser energy may be deliveredfrom a plurality of fixed probe locations. Each pulse will typicallyhave an energy of less than 1 mJ, and total laser energy directed to thepars plana may be less than 40 J. The pulsed laser energy will typicallyhave a duty cycle of about 50% or less, or even a duty cycle of about20% or less.

In many embodiments, a first portion of the pulsed laser energy isdirected to a first arc about the optical axis of the eye. The first arcwill typically be disposed on a superior region of the eye. A secondportion of the pulsed laser beam may be directed toward a second arcabout the optical axis of the eye, the second arc being spaced away fromthe first arc and disposed along an inferior region of the eye.

In some cases, the tip of the probe may be positioned in contact withthe surface of the eye by sliding the tip of the probe in alignment withthe pars plana during delivery of the pulsed laser energy.

Another aspect of the invention provides a method of reducing excessiveintraocular pressure in an eye. A pulsed laser beam is transmitted to acircumferential series of tissue regions of an eye by the followingsteps. A tip of a probe is positioned in contact with the surface of theeye in a position at least 3 mm posterior of the limbus. The pulsedlaser beam is directed from the positioned tip of the probe from theposition toward an associated tissue region of the eye such thatassociated tissue region is treated and the coagulation within the eyeis inhibited. The tip of the probe is re-positioned in contact with thesurface of the eye in another position disposed at least 3 mm posteriorof the limbus and circumferentially offset from the treated region aboutan optical axis of the eye and the pulsed laser beam is again directedfrom the probe to an associated tissue region until the circumferentialseries of tissue regions have been treated. The pulsed laser beam isdelivered while the probe is maintained at each of the positions towardthe associated tissue regions of the eye such that an aggregate amountof the pulsed laser beam delivered to the tissue regions alleviates theexcessive intraocular more than five months after the tissue regionshave been treated.

Another aspect of the invention provides a method for treating an eye byreducing intraocular pressure. A tip of a probe is positioned in contactwith the surface of the eye so that the tip of the probe is posteriorthe limbus of the eye by a desired distance. The tip of the probe ismoved across the surface of the eye while the tip of the probe ismaintained at the desired distance posterior the limbus of the eye.Pulsed laser energy is delivered toward a region of the eye posterior tothe limbus while the tip of the probe is slid across the eye andmaintained in contact with the surface of the eye.

Another aspect of the invention provides a hand-holdable device fordelivering optical energy to treat an eye. The device comprises ahand-holdable elongate member and a contact member disposed on an end ofthe elongate member. The hand-holdable elongate member defines atreatment axis and is adapted to receive an optical fiber for deliveringoptical energy along the treatment axis. The contact member comprises areference element and defines a contact surface. The contact surface isplaced in direct contact with the eye and the reference element isaligned with a reference feature of the eye. The contact surfaceconforms to a region of the surface of the eye and the treatment axisforms a predetermined, non-zero angle with the optical axis of the eye.

The contact surface can be placed in direct contact with the eye and thereference element can be aligned with a reference feature of the eyesuch that the treatment axis is perpendicular to the surface of the eye.

The contact surface will typically conform to the shape of the sclera ofthe eye at the limbus of the eye when the contact surface is placed indirect contact with the eye and the reference element is aligned withthe reference feature of the eye.

The device may further comprise an optical energy source coupled to theelongate member. The delivered optical energy may comprise light energyfrom one or more light emitting diodes of the optical energy source.Typically, the delivered optical energy may comprise light energy fromone or more lasers of the optical energy source. The delivered opticalenergy may be pulsed and have a duty cycle of about 50% or less or evenabout 20% or less.

The hand-holdable device will typically be adapted to deliver opticalenergy to a region of the eye posterior to the limbus when the contactsurface is placed in direct contact with the eye and the referenceelement is aligned with a reference feature of the eye. The region ofthe eye posterior to the limbus may be selected from the groupconsisting of the pars plana of the eye, the pars plana-pars plicatajunction of the eye, and the posterior portion of the pars plicata ofthe eye.

The contact surface of the contact member may define a protrudingoptical energy delivery tip disposed along the treatment axis.

Typically, the reference feature comprises a reference edge shaped toconform with the outer edge of the limbus of the eye.

An optical energy output aperture may be spaced away from the referenceedge by at least about 3 mm to facilitate optical irradiation over atleast one of the pars plana of the eye, the pars plana-pars plicatajunction, and the posterior portion of the pars plicata of the eye.

In many embodiments, the contact surface may comprise a first siderelief and a second side relief opposite the first side relief. Thefirst side relief and the second side relief are adjacent the referenceelement of the contact surface with a width of the contact surfacetherebetween. The width of the contact surface is sized to contact atreatment region of the eye along a plurality of circumferentiallyadjacent treatment regions forming an arc centered about the opticalaxis of the eye. The circumferentially adjacent treatment regions spacedapart from each other by from 5° degrees to 30° degrees, for example, byabout 10° degrees.

Another aspect of the invention provides a device for delivering opticalenergy to treat an eye, the eye having a pars plana. The devicecomprises a handpiece, a contact member, and a laser tip. A contactmember is disposed on an end of the handpiece. The contact membercomprises a target tissue reference element and a treatment site spacingreference element and defines a contact surface. The laser delivery tipis adapted to couple with an optical energy source. The laser deliverytip is positioned relative to the target tissue reference element suchthat when the contact surface is placed in direct contact with an outersurface of the eye with the target tissue reference element aligned witha reference feature of the eye and optical energy is delivered from thelaser delivery tip, the optical energy is directed toward the pars planaat an associated treatment site. The laser delivery tip is positionedrelative to the treatment site spacing reference element such that acircumferential series of treatment sites are defined when the contactsurface is repeatedly placed in direct contact with an outer surface ofthe eye with the target tissue reference element aligned with areference feature of the eye and the treatment site spacing referenceelement aligned with a feature of a prior treatment and delivering anamount of pulsed laser energy to the pars plana of the eye at anassociated treatment site. Delivery of an amount of pulsed laser energyfrom the circumferential series of treatment sites to the pars planathat is insufficient to effect therapeutic photocoagulation can besufficient to increase uveoscleral outflow so as to maintain a reductionfrom the pre-laser treatment intraocular pressure.

In another aspect of the invention, a handpiece which is adapted todirect and deliver optical energy in a predetermined direction and issuitable for delivery of optical energy to a patient's eye is provided.The predetermined direction is defined as the optical axis of thehandpiece. The eye has a shaped sclera, a cornea, a limbus, and anoptical axis. The handpiece incorporates pieces, portions or featuresthat aid in the repeatable application of the handpiece with respect tocertain features of the patients's eye. These reference features may beeither permanent or temporary. They are provided with respect totreatment angle or direction of the optical output axis, with thetreatment axis essentially not parallel to the optical axis of thepatient's eye. They may be provided with one or more of the followingparameters: locational position, indentation pressure, or depth spacingbetween discrete treatment sites.

In many embodiments, the method of delivery of optical energy from itssource to its treatment target includes one or more optical fibers.

In many embodiments, the source of optical energy delivered is intendedto be one or more lasers.

In many embodiments, the source of optical energy delivered is intendedto be one or more light emitting diodes (LEDs).

In many embodiments, the treatment angle/direction is essentiallynormal, i.e., perpendicular, to the reference surface. The referencesurface may be, for example, the sclera or the cornea.

In many embodiments, the feature facilitating placement with respect toa reference surface is one or more curves or facets approximating aportion of a sphere. The feature facilitating placement with respect toa reference surface may be one or more curves or facets approximating aportion of a concave sphere.

In many embodiments, the locational reference is at least partly derivedfrom the limbus, i.e., the ocular region of intersection and transitionbetween the corneal and scleral curves.

In many embodiments, the specific dimensional reference from the limbusis 0 to 4 mm, and may be in a direction anterior or posterior to thelimbus.

In many embodiments, the reference for indentation depth or pressure isat least partly derived from the scleral surface.

In many embodiments, the indentation depth measured from the referencesurface in its natural position is between 0 and 1.5 mm.

In many embodiments, the reference for indentation depth or pressure isat least partly derived from the corneal surface.

In many embodiments, the reference for spacing between adjacenttreatment sites is at least partly derived from one or more previoustreatment sites. The spacing between adjacent treatment sites may besuch so as to permit 1 to 6 application sites per clock-hour, i.e., 5 to30 degree angular spacing, or 12 to 72 sites per full treatmentcircumference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1, 2 and 4 illustrate various embodiments of a contact probe ofthe present invention.

FIG. 3 illustrates elements of the eye in relation to a contact probe ofthe present invention.

FIG. 5 shows a cross section of a contact probe according to embodimentsof the present invention.

FIG. 5A shows a front view of a contact probe according to embodimentsof the present invention.

FIGS. 6A-6E shows a method of treating the eye using a contact probeaccording to embodiments of the present invention.

FIG. 7 shows a chart of exemplary experimental results of a conductedstudy using devices and methods according to embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

In embodiments of the present invention, a laser energy deliveryhandpiece 100 is provided that is specifically designed for theefficient transconjunctival/transscleral delivery of laser energy, forexample, infrared laser energy from a pulsed 810 nm diode laser, overthe posterior region of the pars plicata, over the pars plana-parsplicata junction, and/or over the pars plana. Optical energy from othersources, for example, light emitting diodes (LEDs), may be delivered aswell.

A footprint contact surface 110 of the handpiece 100 is designed so thata fiber optic 120 coupled to the handpiece 100 has a protrudinghemispherical tip 125 that is about 3 mm posterior to the limbus at any360° location, when in normal contact with the conjunctiva/sclera andwith the small radius next to the limbus, in particular, the outer edgeof the limbus.

The footprint contact surface 110 is designed to ensure a radialorientation of the laser beam so that the laser energy is alwaysdirected substantially perpendicular to the conjunctiva/sclera point ofindentation.

In various embodiments, the laser beam output tip 125 protrudes from0.25 mm to 1.0 mm, preferably 0.75 mm, beyond the contact surface.

The indentation of the laser beam output tip 125 maximizes thetransmission of infrared laser energy through the conjunctiva and scleraand provides the beam divergence to irradiate all ciliary bodystructures from the anterior (pars plicata) through the posterior (parsplana) portions of the ciliary body.

The footprint contact surface 110 is designed to allow the surgeon toadminister the treatment either with a continuously 360° sliding motionover the conjunctiva overlying the pars plana or, with a series ofindividual applications with precisely defined angular spacing or radialdisplacements.

The footprint contact surface 110 can provide a radial displacement of5° or 10° or 20°, and the like for a treatment density over a 360°radial area at the treatment site with, 72 or 36 or 18 applicationsrespectively. In some embodiments, a lateral edge 160 to an identationmark of the laser beam output tip 125 spaces each application by 10°over the sclera and allows 36 individual applications in the 360° radialtreatment area.

In some embodiments, the footprint contact surface 110 slides around thetreatment area while the laser continuously delivers laser energy asopposed to individual spaced applications described in the previousembodiment.

The continuously emitted laser energy that is delivered while thefootprint contact surface slides over the sclera can be seen as a paintdelivered with a sliding brush.

Both modalities of the prior paragraph are intended to treat the area ofpigmented ciliary body epithelium cells as defined by the surgeon. Whenapplied ab-externo with continuously sliding motion, for example in twosteady strokes, with an upper 180° in one move and the lower 180° inanother move, a low power pulsed laser emission is “painted” over theciliary body. This provides an irradiation for all the ciliary bodyepithelium cells in a movement analogous to a paintbrush of photothermalenergy sweeping over the eyeball with the power and sweeping timedetermined by the surgeon.

FIG. 1 illustrates a laser energy delivery handpiece 100 according toembodiments of the present invention. Laser energy delivery handpiece100 comprises an elongate body 101 and an end portion 130 disposed onone end of the elongate body 101. Laser energy delivery hand piece 100defines a treatment axis 105 and is adapted to receive a fiber optic 120for laser surgery on a patient's eye E. The eye E has a shaped sclera, alimbus and an optical axis 200. End portion 130 of the laser energydelivery handpiece 100 define a contact surface 110 that conforms to theshape of the sclera at the limbus when the axis 105 of the handpieceforms a predetermined angle 600 relative to the optical axis 200 of theeye E. The contact surface 110 conforms to the shape of the sclera atthe limbus when the axis of the handpiece 100 is substantiallyperpendicular to the conjunctiva-sclera point of indentation of the eyeE.

The contact surface 110 may have a single radius of curvature across thecontact surface 110 and no sharp edges.

In some embodiments of the present invention, the laser energy deliveryhandpiece 100 has an input end, an output end, a top, a bottom andsides. Elongate body 101 holds the fiber optic 120 and end portion 130is contoured.

In some embodiments, the footprint of the contact surface 110 shows theposition of a protruding hemispherical laser beam output tip 125, orother non-blunt geometry, with respect to a limbal placement edge 115,e.g., the short side of the contact surface 110. Limbal placement edge115 has a contact surface contour that conforms to the limbus and isgenerally circularly concave with a radius of about 5.25-6.0 mm. Thelaser beam output tip 125 is, in many embodiments, at 3.0 mm distancefrom the limbal placement edge 115 to facilitate the optimal irradiationover the eye's pars plana-pars plicata junction and/or over the eye'spars plana, from the limbus 20 points to the anterior portion of thepars plana in the normal anatomy of the human eye as illustrated in FIG.3.

The two lateral placement contoured edges 160, e.g., the longer sides ofthe footprint, indicate a 5°-20°, and more particularly a 10° radialdisplacement from the laser beam output tip 125. The edges 160 maycomprise side reliefs, one on each edge, extending from contact surface110. Also, the edges 160 may each define lines which intersect at thecenter of curvature of limbal placement edge 115.

FIG. 2 shows the laser energy delivery handpiece 100 positioned againstthe eye E with the short limbal placement edge 115 next to the limbusand directing the laser energy radially to the eyeball center over thepars plana-pars plicata junction, generally indicated by the axis 105.Alternatively, the distance between short limbal placement edge 115 andtip 125 will be such that the laser energy is directed to the eyeballcenter over the pars-plana or any structure posterior the limbus.

FIG. 3 shows the surgical eye anatomy relevant to the handpiece. Thislaser therapy may target the cilary body that spans from the posteriorpars plicata to the pars plana. Alternatively, the pars plana may betargeted and the pars plicata, ciliary body, and other ciliary processesavoided. The short limbal placement edge 115 is always kept next to theexternal limbus line (CU cornea-limbus junction). In this way,protrusion of the laser output tip 125, which is about 3 mm posteriorthe limbus, directs a diverging beam that irradiates a large portion ofthe ciliary body in the posterior pars plicata and in the pars plana.Alternatively, the laser output tip 125 may be spaced away from theshort limbal placement edge 115 such that laser output tip 125 directs adiverging beam that irradiates the pars plana while avoiding the parsplicata, ciliary body, and other ciliary processes.

FIG. 5 shows a cross section of laser energy delivery handpiece 100.Laser energy delivery handpiece 100 comprises elongate body 101 and endportion 130. Handpiece 100 defines treatment axis 105 and houses fiberoptic 120 so that fiber optic 120 directs optical energy along treatmentaxis 105. End portion 130 comprises a contoured surface 110 having aradius of curvature shaped to conform with the shape of the sclera ofthe limbus of the eye when surface 110 is placed in contact with thesurface of the eye E. As shown in FIG. 5A, contoured surface 110comprises lateral edges 160 and a limbal placement edge 115. Laserenergy is delivered from protruding tip 125 protruding from contouredsurface 110. Protruding tip 125 is spaced away from limbal referenceedge 115 at a predeteremined distance, usually about 3 mm, e.g. 3.4 mm,from limbal reference edge 115. The limbus of the eye E can serve as areference point for the placement of handpiece 100. Limbal referenceedge 115 is placed adjacent the outward facing edge of the limbus suchthat opening 125 directs laser energy over the pars plana and/or parsplana-pars plicata junction and treatment axis 105 is parallel to thesurface of the eye.

FIGS. 6A-6E show an exemplary method of using laser eye deliveryhandpiece 100 to delivery laser energy to treat an eye. As shown in FIG.6A, handpiece 100 is positioned at a first treatment region so thatcontoured surface 110 is in contact with the sclera of the eye E andlimbal reference edge 125 is adjacent the limbus, the region of the eyebetween the cornea and the sclera. Treatment axis 105, as defined byhandpiece 100, forms a predetermined angle, for example, a 40° degreeangle, with optical axis 200 of the eye E. Tip or opening 125 is spacedposterior the limbus with a distance 505 which may be, for example,about 3 mm. Laser energy is directed through tip or opening 125 todirect laser energy to the pars plana.

In an exemplary embodiment, the directed laser energy comprises pulsedlaser energy from an infrared laser that can be operated in pulsed aswell as continuous wave emission modes. For example, the pulsedcontinuous wave infrared laser has about a 30% duty cycle, with an “on”time of about 500 μs and an “off” time of about 1100 μs, about a 15%duty cycle, with an “on” time of about 300 μs and an “off” time of about1700 μs, or about a 10% duty cycle, with an “on” time of about 200 μsand an “off” time of about 1800 μs. Pulsed laser energy can avoidundesired thermal damage to a target by allowing the target to coolduring the “off” time of the laser before the next pulse of laser energyis delivered during the “on” time. The duty cycle may be selected sothat cumulative thermal buildup, caused by insufficient cooling duringthe “off” time of the laser beam, is avoided. Thus, laser damage can bereduced to a minimum level sufficient to trigger a biological responseneeded for lowering of intraocular pressure (IOP).

In the exemplary procedure described with reference to FIGS. 6A-6E, aduty cycle of 15% is used. The power of the laser is set at 1500 mW andthe duration of irradiation for each spot is 300 ms.

As shown in FIG. 6B, laser energy is directed toward a first spot 601.Afterwards, handpiece 100 is repositioned, for example, by movinghandpiece 100 over, to a second treatment region adjacent the firsttreatment region. Handpiece 100 may be moved by sliding it over to thesecond treatment region from the first treatment region whilemaintaining contact surface 110 in contact with the surface of the eye.Or, handpiece 100 may be removed from contact from the surface of theeye at the first position and placed in contact with the eye again atthe second position. Edges 160 may have side reliefs which may indentthe surface of the eye, with the indentations providing a reference tohelp reposition handpiece 100. At the second position, handpiece 100 isagain positioned so that limbal reference edge 125 is adjacent thelimbus.

As shown in FIG. 6C, laser energy is directed toward a second spot 602.Thus, first spot 601 and second spot 602 are equidistant from theoptical axis 200 of the eye E. This process of repositioning handpiece100 and directing laser energy toward the pars plana is repeated for athird spot, a fourth spot, and so forth. For example, as shown in FIG.6D, laser energy is directed toward a first treatment point at 320° on aright eye, then toward a second treatment point at 330°, and thensuccessively clockwise every 10° until a point at 90°, e.g., towardpoints at 340°, 350°, 360°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, andthen 90°, thereby creating a first 130° arc of treatment points on thesuperior side of the eye E. Thus, a series of individual applicationswith precisely defined angular spacing or radial displacements are made.A second 130° arc of treatment points on the inferior side of the eye Emay then be created, starting from directing laser energy toward thepoint at 220° and then toward successively counter-clockwise pointsevery 10° until a point at 100°.

As shown in FIG. 6E, a similar procedure of directing laser energytoward a plurality of treatment points can be made on the left eye.Laser energy is directed toward a point at 40° and then successivelycounterclockwise until a point at 270°, creating a first 130° arc oftreatment points. Then, laser energy can be directed toward a point at140° and then successively clockwise every 10° until a point at 260°. Insome embodiments, laser energy may be exposed to each point for about1.0 seconds at a power of 1.5 W. The duty cycle of the laser energy maybe 10%, with an “on” time of about 200 μs and an “off” time of about1800 μs. The laser energy may be pulsed to avoid undesired thermaldamage, for example, about 500 pulses may be delivered for each exposureof about 1.0 seconds. The eye E may also be treated at more or lesstreatment points at different areas, for example, the eye E may betreated so that a superior arc and an inferior arc of each of 150° oreven 180° can be created. For example, 20 stationary applications over360° may be made, with 5 stationary applications per quadrant. Treatmentpoints may also be alternatively spaced apart from each other by otherangles besides 10°, for example, by providing handpieces with differentdistances between edges 160. The pulsed laser systems and methods maycomprise a MicroPulse™ Laser System and method.

In other embodiments, handpiece 110 may be slid or “painted” over atargeted region of the eye all the while laser energy is being emitted.For example, tip 115 may first be positioned about 3 mm posterior thelimbus at the 10 o'clock or 300° position of the eye and gradually slidclockwise until the 2 o'clock or 60° position, all the while exposingthe targeted region of the eye, e.g., the pars plana, with pulsed laserenergy. Thus, if the width of surface 110 spans 30°, a superiortreatment arc of 150° can be created. A inferior treatment arc of 150°can likewise be created by positioning tip 115 about 3 mm posterior thelimbus at the 8 o'clock position or 240° and gradually sliding handpiece110 until it reaches the 4 o'clock position or 120°, all the whileexposing the targeted region of the eye, e.g., the pars plana, withpulsed laser energy. In exemplary embodiments, the duration of laserenergy exposure for each treatment arc may be 50 seconds and the powerof the laser may be 2 Watts. A total of 31,250 pulses at a rate of 625pulses per second may be made during the 50 seconds. Each pulse may havean energy of 1.0 mJ. The size of the treatment arcs may vary. Thetreatment arcs, for example, may comprise a 180° superior arc and a 180°inferior arc.

EXPERIMENTAL SECTION Experiment A

An initial study using a handpiece with a contact probe similar to thosedescribed above was conducted at the National University Hospital inSingapore. In the study, treatment procedures similar to those describedabove were conducted on a number of glaucomatous eyes. This initialstudy tracks glaucomatous eyes for about 6 months, the treated eyesbeing treated with the aforementioned handpiece and a treatmentprocedure using pulsed laser energy.

Patients with advanced glaucoma refractory to maximum tolerated medicaland surgical treatment and a visual acuity of worse than 6/60 wereincluded in the study. Patients with recent eye surgery within 3 monthsof enrollment, active ocular inflammation or inability to give informedconsent were excluded.

The procedure was performed by a single surgeon to patients under localanesthesia. The contact probe was designed for accurate positioning of afiber optic at 3.4 mm behind the limbus of the eye.

The laser settings were 2000 mW, applied over a total duration of 100 s,with a pulse duration of 0.6 s and a pulse interval of 1.1 s. Shots wereapplied over 360° avoiding the 3 o'clock and 9 o'clock regions and anyareas of thinning.

The main outcome measure was success of treatment, defined as a 30% ormore reduction of IOP from baseline or an IOP of less than 21 mm Hg at 6month follow-up.

23 eyes of 23 patients were treated. The patients had a mean age of62.9±20.3 years. The mean duration of follow-up was 5.3±1.5 months. Themean pre-treatment IOP was 37.1±9.5 mm Hg.

TABLE 1 below summarizes mean IOP before and after treatment at 1 day, 1week, 1 month, 3 months, and 6 months post-op. All mean post-treatmentIOPs were significantly lower than the pre-treatment IOPs (pairedStudent's t-test, p<0.001).

TABLE 1 POST-OP IOP MEAUSREMENTS Mean IOP Meant IOP Reduction Time Point(mm Hg) (%) Baseline 37.1 ± 9.5  — 1 day post-op 28.7 ± 10.8 24.0 ± 17.11 week post-op 26.6 ± 9.8  30.9 ± 18.7 1 month post-op 22.2 ± 7.0  38.2± 19.6 3 months post-op 22.9 ± 8.9  35.4 ± 24.2 6 months post-op 23.7 ±9.7  37.6 ± 19.4

The rate of success of the treatment, defined as a 30% or more reductionfrom baseline or a final IOP of less than 21 mm Hg at the 6th monthfollow-up visit. The success rate was 38% at 1 day, 57% at 1 week, 76%at 1 month, 80% at 3 months and 69% at 6 months. None of the patientshad hypotony or loss in their best corrected visual acuity.

Experiment B

A similar study using a handpiece with a contact probe similar to thosedescribed above was conducted also at the National University Hospitalin Singapore. In the study, treatment procedures using pulsed laserenergy similar to those described above were conducted on a number ofglaucomatous eyes. This study tracks the treated eyes for up to 18months.

The MicroPulse™ procedure was performed by a single surgeon in theoutpatient setting. Regional anesthesia with peribulbar or retrobulbarinjection of 2% lidocaine was given prior to the procedure. Scleraltransillumination was used to identify the position of the ciliary bodyas well as any areas of thinning. A diode laser emitting ball-lens tipcontact probe, which is similar to those described above, was appliedaxially at the limbus. This probe housed a quartz fiberoptic of 600 μmin diameter. Its end protrudes 0.7 mm from the handpiece. The probe wasspecifically designed to allow positioning of the fiberoptic at 3.4 mmbehind the surgical limbus, i.e., the distance from the reference edgeof the contact surface of the probe to the fiberoptic was 3.4 mm. Thelaser settings were 2000 mW, over a total duration of 100 s, with atrain of repetitive pulses each with a pulse duration of 0.5 ms and apulse interval of 1.1 ms. The treatment was applied by “painting” ormoving the probe continuously over 360 of the ciliary body, avoiding the3 and 9 o'clock meridians and any area of thinned sclera. Total energydelivered to the ciliary body was 60-90J.

The amount of intraoperative pain experienced by the patient wasrecorded and additional regional anesthesia was administered asrequired. Postoperatively, topical prednisolone acetate 1% wasprescribed four times daily along with oral mefenamic acid for 5 days.Follow-up examinations were performed at 1 day, 1 week, 1 month, 3months, 6 months, 12 months, and 18 months. Pain scoring, visual acuity,Goldman applanation tonometry, slit lamp biomicroscopy and dilatedfundus examinations were carried out at every visit. Retreatment over360 degrees was performed between 1 to 3 months if IOP reduction wasless than 20%.

Statistical analysis was performed using SPSS software version 15.0.Means were compared using the two-tailed paired Student's t-test, withp<0.05 being considered significant.

46 eyes of 44 patients were evaluated in this study. The mean age of thepatients was 63.2±16.0 years. There were 36 men (81.8%). Right eyes of17 (38.6%) patients, left eyes of 23 (52.3%) patients and both eyes of 2patients underwent MicroPulse™ treatment with TSCPC. TABLE 2 below showsthe distribution of glaucoma diagnoses. Four eyes received retreatmentbetween 1 to 3 months after the initial laser.

TABLE 2 DISTRIBUTION OF GLAUCOMA DIAGNOSES Type of Glaucoma No. (%)Neovascular glaucoma 17 (38.6%) Primary open angle glaucoma 10 (22.7%)Primary angle closure glaucoma 10 (22.7%) Others  7 (16.0%)

TABLE 3 below summarizes mean IOP before and after treatment at 1 day, 1week, 1 month, 3 months, 6 months, 12 months, and 18 months post-op. Allmean post-treatment IOPs were significantly lower than the pre-treatmentIOPs (paired Student's t-test, p<0.001). The mean duration of follow-upwas 16.2±4.5 months.

TABLE 3 POST-OP IOP MEAUSREMENTS Mean reduction in IOP from Mean IObaseline Time Point (mm Hg) (%) Baseline 39.1 ± 12.7 —  1 day 31.1 ±13.5 21.6  1 week 28.1 ± 12.1 28.1  1 month 27.6 ± 12.8 28.4  3 months27.2 ± 12.8 23.5  6 months 26.0 ± 13.4 27.2 12 months 26.5 ± 12.6 27.318 months 26.9 ± 11.8 30.5

As shown in FIG. 7, the decrease in IOP appears to be gradual andsustained over 6 months. All patients who required systematicacetazolamide (n=6) prior to the treatment were able to discontinue thedrug by the first postoperative day. The mean number of topicalanti-glaucoma medication was reduced from 1.8±1.1 to 1.4±1.1 at 6 monthsfollow up (p=0.003).

During the procedure, 15 patients (34.0%) reported some pain but foundit to be tolerable and did not require additional anaesthesia. Twopatients (4.0%) required additional regional anaesthesia. Postprocedure, 7 patients (15.9%) reported mild pain on the first day. Nonerequired oral analgesia beyond the first day of treatment. All patientshad mild postoperative inflammation at day 1 in the form of 1+ anteriorchamber cells with slight conjunctival hyperemia. This inflammationresolved by 2 weeks post treatment in 40 patients (90.9). None of thepatients experienced deterioration of their best-corrected visual acuityat final follow-up. One patient who had no light perception before theMicroPulse™ procedure underwent evisceration at 1 month for conrealperforation secondary to infection of a pre-existing bullouskeratopathy. No patient developed hypotony, defined as an IOP of lessthan 5 mm Hg.

The IOP lowering efficacy of the studied method is comparable toconventional ciliary body photo-coagulation. The rapidity of IOPreduction, seen as early as 1-day post treatment, is an additionaladvantage over traditional laser treatment. The rapid reduction in IOPseen may be due to enhanced outflow facility from the uveal andsuprachoroidal spaces as the novel probe targets the ciliary bodyepithelium of the pars plicata and/or the pars plana. Low laser pulsesallow for repetitive series of sub-threshold intensity pulses of energyto be delivered with rest periods in between. “Painting” may also allowfor a more even distribution of effect and a larger area to be treatedcompared to conventional laser treatment. A biological response may betriggered to lower IOP and yet excessive thermal damage to the ciliaryepithelium and processes is avoided, as seen in histological specimensafter conventional laser treatment. The limitation of adjacent tissuedamage seen in the MicroPulse™ procedure may also explain the absence ofcomplications such as hypotony.

It is to be understood that the above description is intended to beillustrative and not restrictive. Many embodiments will be apparent tothose of skill in the art upon reviewing the above description. Thescope of the invention should, therefore, be determined with referenceto the appended claims, along with the full scope of equivalents towhich such claims are entitled.

1. (canceled)
 2. A laser treatment method for treating an eye byreducing intraocular pressure, the method comprising: positioning a tipof a laser probe in contact with a surface of the eye so that the tip ofthe probe is posterior to a limbus of the eye by a desired distance;sweeping the tip of the probe across the surface of the eye in an arcmotion while the tip of the probe is maintained at the desired distanceposterior to the limbus of the eye; delivering pulsed laser energytoward a first treatment region of the eye posterior to the limbus whilethe tip of the probe is swept across the eye and maintained in contactwith the surface of the eye; repositioning the tip of the probe toanother position posterior to the limbus of the eye by the desireddistance and circumferentially offset from the first treatment regionabout an optical axis of the eye; and delivering pulsed laser energytoward a second treatment region of the eye with the tip of the probe incontact with the surface of the eye while sweeping the tip of the probeacross the eye in the arc motion, wherein an aggregate amount of thepulsed laser energy reduces intraocular pressure of the eye.
 3. Themethod of claim 2, wherein a treatment axis along which the pulsed laserenergy is delivered is generally perpendicular to an outer surface of asclera of the eye.
 4. The method of claim 2, wherein sweeping comprisesuniformly sliding the tip of the probe in a treatment arc range between130 degrees and 180 degrees around the limbus of the eye.
 5. The methodof claim 4, wherein the treatment arc range is 150 degrees.
 6. Themethod of claim 4, wherein a duration of laser energy exposure for eachtreatment arc is 50 seconds or less at a power of 2000 mW.
 7. The methodof claim 2, wherein sweeping is performed in continuous clockwise andcounter-clockwise motions.
 8. The method of claim 2, wherein sweepingcomprises a series of discrete spaced applications.
 9. The method ofclaim 2, wherein sweeping avoids 3 o'clock and 9 o'clock regions of theeye.
 10. The method of claim 2, wherein sweeping is carried out inquadrant regions of the eye.
 11. The method of claim 2, wherein sweepingcomprises continuously sliding the tip of the probe along a superior arcof 150 degrees around the limbus of the eye in the first treatmentregion of the eye.
 12. The method of claim 11, wherein sweeping furthercomprises continuously sliding the tip of the probe along an inferiorarc of 150 degrees around the limbus of the eye in the second treatmentregion of the eye.
 13. The method of claim 2, wherein sweeping,delivering, and repositioning is repeated to transmit the pulsed laserenergy in an annular pattern to tissue regions of the eye.
 14. Themethod of claim 2, wherein the desired distance is between about 2 mm to3 mm.
 15. The method of claim 2, wherein the desired distance is greaterthan about 3 mm.
 16. The method of claim 2, wherein the first and secondtreatment regions comprise a pars plana of the eye, a pars plana-parsplicata junction, or a posterior portion of a pars plicata of the eye.17. The method of claim 2, further comprising selecting a duty cycle forthe pulsed laser energy that is configured to reduce undesired thermaldamage to a tissue, wherein the selected duty cycle provides asufficient off time to prevent cumulative thermal buildup in the tissue.18. The method of claim 17, wherein the pulsed laser energy is deliveredwith a duty cycle of about 30% or less.
 19. The method of claim 2,wherein the aggregate amount of the pulsed laser energy is between about40 J and 100 J and is sufficient to maintain a reduction from apre-laser treatment intraocular pressure more than 5 months after thepulsed laser energy is delivered.
 20. The method of claim 2, whereinpositioning the tip of the probe comprises positioning a referencestructure of the probe tip in alignment with a reference feature of theeye such that an output aperture of the tip for delivering pulsed laserenergy is posterior to the limbus of the eye by the desired distance.21. The method of claim 20, wherein the reference structure of the probetip is at an edge of the tip that extends between opposed lateralplacement sides of a tip contact surface, and wherein sweeping comprisesmoving the probe in the arc motion around the limbus with reference tothe reference structure.